Dancing with Moxe.

Resistance to antibody-targeted therapy for heme malignancies commonly occurs when the cancer cell finds an alternative signaling pathway to lead its replication efforts in the face of antibody blockade. Solution? Tag the antibody with a poison. That’s the basic idea behind “immunotoxins” such as the popular Kadcyla for HER2(+) breast cancer and the newer BIND-014 for prostate cancer. Moxetumomab pasudotox (aka Moxe) is the newest of these antibody-poisons, but it takes cell kill to the next level. It is a CD22-antibody tagged not to a traditional chemo but to an actual biotoxin made byPseudomonas aeruginosa. A phase 3 trial presented in abstract form reports a complete response with Moxe in 33 (41%) of 80 patients treated for refractory hairy cell leukemia, which typically expresses a whole lotta CD22. What’s more, 24 (30%) patients remained completly free of disease more than 6 months out from treatment. TBL: The best answer for heme malignancies refractory to standard therapy may be to pop a Moxe. | Kreitman, ASCO 2018